Unable to do Serial Communication between Arduino and Matlab

I am trying to send data from MATLAB to Arduino using the following code for Arduino and the second one for the MATLAB.

Both codes work fine and when I press 1 LED lights up and when press 2 LED switches off. But actually what I am trying to do is when MATLAB runs code it automatically sends 1 to the Arduino and the LED turns on. I have tried many changes but can't do this.

When I am trying to run the third code (given below) the Arduino status LED blinks to show that it received something, but my actual LED which is connected to pin 13 is still off.

int ledPin=13;
int matlabData;

void setup() 
{
  pinMode(ledPin,OUTPUT);
  Serial.begin(9600);
}

void loop()
{

    if(Serial.available()>0) // if there is data to read
     {
      matlabData=Serial.read(); // read data
      if(matlabData==1)
        digitalWrite(ledPin,HIGH); // turn light on
      else if(matlabData==2)
        digitalWrite(ledPin,LOW); // turn light off
    }
  }

(MATLAB)

clear all
clc

answer=1; % this is where we'll store the user's answer
arduino=serial('COM4','BaudRate',9600); % create serial communication object on port COM4

fopen(arduino); % initiate arduino communication

while answer
fprintf(arduino,'%s',char(answer)); 
answer=input('Enter led value 1 or 2 (1=ON, 2=OFF, 0=EXIT PROGRAM): '); 
end

fclose(arduino);

(MY edit code)

clear all
clc 
answer=1; 
arduino=serial('COM4','BaudRate',9600); 
fopen(arduino);  
%while answer 
printf(arduino,'%s',char(answer)); 
answer='1'
%end
fclose(arduino);

Answer 1

[Ishi]

clear all
clc

answer=1; 
arduino=serial('COM3','BaudRate',9600); 

fopen(arduino); 

while answer
    answer=input('Enter 1 or 2, 0=EXIT PROGRAM: '); 

      fprintf(arduino,'%d', answer); 
  end
  fclose(arduino);

Answer 2

[Madhu Govindarajan]

If you are trying to turn on LEDs using MATLAB on an Arduino board, you can simplify this by downloading the support package from here - http://www.mathworks.com/hardware-support/arduino-matlab.html

And of course you can do much more using the support package.